Copolymer vulcanizates for use in contact with oxymethylene ether comprising media

ABSTRACT

The present invention relates to (halogenated) copolymer vulcanizates and the use thereof in devices such as seals, tank linings, o-rings or hoses which are in contact with liquid medium comprising oxymethylene ether.

FIELD OF INVENTION

The present invention relates to (halogenated) copolymer vulcanizatesand the use thereof in devices such as seals, tank linings, o-rings orhoses which are in contact with liquid medium comprising oxymethyleneether.

TEHCNICAL BACKGROUND

Combustion engines are under criticism due to pollution of theenvironment. Future powertrain technologies will be measured against CO₂neutrality, sustainability and exhaust emissions, which are statutoryrequirements that take priority and lay the foundations forsustainability. To reach these goals, technical processes usingelectrical energy have been developed to synthesize liquid fuel(“Power-to-liquid”). One approach is to use CO or CO₂ and sustainablyproduced H₂ to synthesize non-toxic or liquid fuels (e.g. benzene,diesel or kerosene) which are CO₂-neutral and sustainable (so called“blue crude”).

Ether-based fuels with C1 building blocks that contain no C-C bonds suchas oxymethylene ether (e.g. OME1) are a particularly effective means ofminimizing emissions with less complex exhaust after treatment. OME1 ismade from methanol on a commercial scale, has a high energy density andhas a cetane number (CN) of about 38. It can be mixed with additives toproduce OME1a diesel fuel (CN 48).

The use of a synthetic oxygenated product as a substitute of gas oil indiesel engines is known for some time EP-A-1 422 285 (2003). A contentof 20 wt.-% OME in diesel leads to soot reduction of more than 60% andto a NOx-emission reduction of 25%.

Compositions comprising diesel fuel (DF) and polyoxymethylenedialkylether (POMDAE) are disclosed in WO-A-08/074704.

The soot production is reduced to 0% if pure OME is used as a fuel ininternal combustion engines. These fuels have the potential to prolongthe use of the efficient internal combustion engines.

However, these oxygenated fuels have different chemical propertiescompared to standard hydrocarbon fuels which leads to new challenges forcomponents and devices which are in contact with oxygenated fuels.Conventionally, several vulcanized rubber products and devices based onsynthetic rubber are in contact with fuel in every combustion engine,e.g. O-ring seals, gaskets, transport lines or hoses.

Unfortunately, not every vulcanized synthetic rubber which is suitablefor use as a products in contact with diesel fuel, can be also use incontact with oxymethylene ether as oxygenated fuels often lead to atremendous swelling of the rubber vulcanizate which makes theirapplication unfeasible. E.g. the polarity of diesel fuel is too similarfor un-polar rubbers like butadiene rubber (BR) orethylene-propylene-diene rubber (EPDM).

The Book of Abstracts of the 5.International Conference of theexcellence cluster “Tailor-Made Fuels from Biomass” discloses on page101-104 swelling experiments with various synthetic rubbers in dieselfuel and in OME. Conventional synthetic rubbers for seals such asnitrile butadiene rubber (NBR) or fluorocarbon rubber (FKM) show astrong swelling in OEM. Suitable synthetic rubbers such as perfluoroelastomer rubber (FFKM) or tetrafluoro ethylene propylene rubber (FEPM)which show a low swelling are uneconomical.

It is difficult to predict the swelling degree of rubber in liquidmedium. Swelling of polymers is typically correlated to the principle of“likes solves likes” and can be expressed by the solubility parameter ofboth materials to assess if there will be swell in the rubber. Intheory, a rubber with a solubility parameter which is close to thesolubility parameter of the medium should swell the most (“similiasimilibus solvuntur”).

The most simple oxymethylene ether is dimethyl ether (DME) and has asolubility parameter of 17.1 MPa^(1/2). OME1 (dimethoxymethane,methylal) with one oxymethylene group more has a solubility parameteraccording to literature of 17.4 MPa^(1/2). It was expected thathydrogenated nitrile rubber (HNBR) with 34 wt.-% acrylonitrile contentwith a solubility parameter of 20.7 MPa^(1/2) would be a good fit andhave low swell. However, unexpectedly a relatively high swell occurred.

It was therefore an object of the present invention to provide elasticvulcanized rubber products (vulcanizates) such as seals, gaskets orhoses which have a low swelling degree in contact with oxymethyleneether or media comprising oxymethylene ether.

SUMMARY OF THE INVENTION

It has now been surprisingly found that—in contrast to the predictedsolubility parameters—vulcanizates comprising copolymer, have a lowswelling degree in oxymethylene ether and are therefore preferablysuited to be used as vulcanizate and devices which are in contact withoxymethylene ether or media comprising oxymethylene ether.

Therefore, the invention describes devices comprising (i) a vulcanizatecomprising copolymer and (ii) a medium comprising oxymethylene ether,wherein the vulcanizate (i) is in contact with the medium (ii).

DETAILED DESCRIPTION OF THE INVENTION

The invention is further described in the following embodiments.

The invention also encompasses all combinations of preferredembodiments, ranges parameters as disclosed hereinafter with either eachother or the broadest disclosed range or parameter.

If not expressly stated otherwise phr refers to parts per hundredrubber.

As used herein the term copolymer vulcanizate denotes a vulcanizateobtained by curing a compound comprising at least one (halogenated)copolymer.

(a) (Halogenated) Copolymer

As used herein, the term copolymer encompasses any polymer whichcontains at least structural units derived from at least one isoolefinand structural units derived from at least one conjugated multiolefin.

The term halogenated copolymer denotes a copolymer which was halogenatedand thus comprises halogen atoms. The term (halogenated) copolymerdenotes copolymer and halogenated copolymer as defined hereinabove.

Preferred (halogenated) copolymers include (halogenated) copolymerscomprising structural units derived from at least one isoolefin and atleast one conjugated multiolefin whereby for halogenated copolymers thestructural units derived from the at least one conjugated multiolefinare at least partially halogenated.

Examples of suitable isoolefins include isoolefin monomers having from 4to 16 carbon atoms, preferably 4 to 7 carbon atoms, such as isobutene,2-methyl-1-butene, 3-methyl-1-butene, 2-methyl-2-butene. A preferredisoolefin is isobutene.

Examples of suitable conjugated multiolefins include isoprene,butadiene, 2-methylbutadiene, 2,4-dimethylbutadiene, piperyline,3-methyl-1, 3-pentadiene, 2,4-hexadiene, 2-neopentylbutadiene,2-methyl-1, 5-hexadiene, 2,5-dimethyl-2, 4-hexadiene,2-methyl-1,4-pentadiene, 4-butyl-1, 3-pentadiene, 2,3-dimethyl-1,3-pentadiene, 2,3-dibutyl-1, 3-pentadiene, 2-ethyl-1, 3-pentadiene,2-ethyl-1, 3-butadiene, 2-methyl-1, 6-heptadiene, cyclopentadiene,methylcyclopentadiene, cyclohexadiene and 1-vinyl-cyclohexadiene.

Preferred conjugated multiolefins are isoprene and butadiene. Isopreneis particularly preferred.

The (halogenated) copolymers may or may not further comprise structuralunits derived from further olefins which are neither isoolefins norconjugated multiolefins.

Examples of such suitable olefins include p-pinene, styrene,divinylbenzene, diisopropenylbenzene, o-, m- and p-methyl-styrene.

The content of structural units derived from conjugated multiolefins ofthe (halogenated) copolymers is typically 0.1 mol-% or more, preferablyof from 0.1 mol-% to 15 mol-%, in another embodiment 0.5 mol-% or more,preferably of from 0.5 mol-% to 10 mol-%, in another embodiment 0.7mol-% or more, preferably of from 0.7 to 8.5 mol-% in particular of from0.8 to 1.5 or from 1.5 to 2.5 mol-% or of from 2.5 to 4.5 mol-% or from4.5 to 8.5 mol-%, particularly where isobutene and isoprene areemployed.

For halogenated copolymer the halogen level is for example of from 0.1to 5 wt. -%, preferably of from 0.5 to 3.0 wt. -% with respect to thehalogenated copolymer.

The halogenated copolymer may be a brominated copolymer or a chlorinatedcopolymer, which are also referred to a bromobutyl rubber andchlorobutyl rubber.

In one embodiment of the invention, the copolymer isisobutylene-isoprene-rubber (IIR, butyl rubber), bromobutyl rubber(BIIR) or chlorobutyl rubber (CIIR).

The term “content” given in mol-% denotes the molar amount of structuralunits derived from the respective monomer in relation to all structuralunits of the (halogenated) copolymer.

In one embodiment the weight average molecular weight of the(halogenated) copolymer is in the range of from 10 to 2,000 kg/mol,preferably in the range of from 20 to 1,000 kg/mol, more preferably inthe range of from 50 to 1,000 kg/mol, even more preferably in the rangeof from 200 to 800 kg/mol, yet more preferably in the range of from 375to 550 kg/mol, and most preferably in the range of from 400 to 500kg/mol.

Molecular weights are obtained using gel permeation chromatography intetrahydrofuran (THF) solution using polystyrene molecular weightstandards if not mentioned otherwise.

In one embodiment the polydispersity of the (halogenated) copolymer isin the range of 1.5 to 4.5 as measured by the ratio of weight averagemolecular weight to number average molecular weight as determined by gelpermeation chromatography.

The (halogenated) copolymer for example and typically has a Mooneyviscosity of at least 10 (ML 1×8 at 125′C, ASTM D 1646), preferably offrom 10 to 80, more preferably of from 20 to 80 and even more preferablyof from 25 to 60 (ML 1×8 at 125′C, ASTM D 1646).

Of particular importance as copolymers are isobutylene-isoprene-rubbers(IIR) and their halogenated derivatives chlorobutyl rubber (CIIR) andbromobutyl rubber (BIIR).

The (halogenated) copolymer may be present in the compound in an amountof 1 to 100 phr, or 10 to 100 phr, or 25 to 100 phr, or 50 to 100 phr,or 70 to 100 phr, or 85 to 100 phr based on the total weight of rubberin the compound (phr).

The compound comprising at least one (halogenated) copolymer may or maynot further comprise at least one secondary rubber being different from(halogenated) copolymers and which are preferably selected from thegroup consisting of natural rubber (NR), epoxidized natural rubber(ENR), polyisoprene rubber, poly(styrene-co-butadiene) rubber (SBR),chloroprene rubber (CR), polybutadiene rubber (BR),perfluoro(halogenated) copolymer (FFKM/FFPM), ethylene vinylacetate(EVA) rubber, ethylene acrylate rubber, polysulphide rubber (TR),ethylene-propylene rubber (EPR), ethylene-propylene-diene M-class rubber(EPDM), polyphenylensulfide, nitrile-butadiene rubber (NBR),hydrogenated nitrile-butadiene rubber (HNBR), propylene oxide polymers,polyisobutylene rubber, star-branched polyisobutylene rubber,poly(isobutylene-co-p-methylstyrene) and halogenatedpoly(isobutylene-co-p-methylstyrene).

The secondary rubber may be present in the compound in an amount of 0 to99 phr, or 0 to 90 phr, or 0 to 75 phr, or 0 to 50 phr, or 0 to 30 phr,or 0 to 15 phr based on the total weight of the rubber in the compound(phr).

The compound comprising at least one (halogenated) copolymer may furthercomprise one or more fillers. The fillers may be non-mineral fillers,mineral fillers or mixtures thereof. Non-mineral fillers are preferredin some embodiments and include, for example, carbon blacks, rubber gelsand mixtures thereof. Suitable carbon blacks are preferably prepared bylamp black, furnace black or gas black processes. Carbon blackspreferably have BET specific surface areas of 20 to 200 m²/g. Somespecific examples of carbon blacks are SAF, ISAF, HAF, FEF and GPFcarbon blacks. Suitable mineral fillers comprise, for example, silica,silicates, clay, bentonite, vermiculite, nontronite, beidelite,volkonskoite, hectorite, saponite, laponite, sauconite, magadiite,kenyaite, ledikite, gypsum, alumina, talc, glass, metal oxides (e.g.titanium dioxide, zinc oxide, magnesium oxide, aluminum oxide), metalcarbonates (e.g. magnesium carbonate, calcium carbonate, zinccarbonate), metal hydroxides (e.g. aluminum hydroxide, magnesiumhydroxide) or mixtures thereof. Dried amorphous silica particlessuitable for use as mineral fillers may have a mean agglomerate particlesize in the range of from 1 to 100 microns, or 10 to 50 microns, or 10to 25 microns. In one embodiment, less than 10 percent by volume of theagglomerate particles may be below 5 microns. In one embodiment, lessthan 10 percent by volume of the agglomerate particles may be over 50microns in size.

Suitable amorphous dried silica may have, for example, a BET surfacearea, measured in accordance with DIN (Deutsche Industrie Norm) 66131,of between 50 and 450 square meters per gram. DBP absorption, asmeasured in accordance with DIN 53601, may be between 150 and 400 gramsper 100 grams of silica. A drying loss, as measured according to DIN ISO787/11, may be from 0 to 10 percent by weight.

Suitable silica fillers are commercially sold under the names HiSil™210,HiSil™233 and HiSil™243 available from PPG Industries Inc. Also suitableare Vulkasil™and Vulkasil™N, commercially available from LANXESSDeutschland GmbH.

High aspect ratio fillers useful in the present invention may includeclays, tales, micas, etc. with an aspect ratio of at least 1:3.Thefillers may include acircular or nonisometric materials with a platy orneedle-like structure. The aspect ratio is defined as the ratio of meandiameter of a circle of the same area as the face of the plate to themean thickness of the plate. The aspect ratio for needle and fibershaped fillers is the ratio of length to diameter. The high aspect ratiofillers may have an aspect ratio of at least 1:5, or at least 1:7, or ina range of 1:7to 1:200. High aspect ratio fillers may have, for example,a mean particle size in the range of from 0.001 to 100 microns, or 0.005to 50 microns, or 0.01 to 10 microns. Suitable high aspect ratio fillersmay have a BET surface area, measured in accordance with DIN (DeutscheIndustrie Norm) 66131, of between 5 and 200 square meters per gram. Thehigh aspect ratio filler may comprise a nanoclay, such as, for example,an organically modified nanoclay. Examples of nanoclays include naturalpowdered smectite clays (e.g. sodium or calcium montmorillonite) orsynthetic clays (e.g. hydrotalcite or laponite). In one embodiment, thehigh aspect filler may include organically modified montmorillonitenanoclays. The clays may be modified by substitution of the transitionmetal for an onium ion, as is known in the art, to provide surfactantfunctionality to the clay that aids in the dispersion of the clay withinthe generally hydrophobic polymer environment. In one embodiment, oniumions are phosphorus based (e.g. phosphonium ions) or nitrogen based(e.g. ammonium ions) and contain functional groups having from 2 to 20carbon atoms. The clays may be provided, for example, in nanometer scaleparticle sizes, such as, less than 25 pm by volume. The particle sizemay be in a range of from 1 to 50 pm, or 1 to 30 pm, or 2 to 20 pm. Inaddition to silica, the nanoclays may also contain some fraction ofalumina. For example, the nanoclays may contain from 0.1 to 10 wt.-%alumina, or 0.5 to 5 wt.-% alumina, or 1 to 3 wt.-% alumina. Examples ofcommercially available organically modified nanoclays as high aspectratio mineral fillers include, for example, those sold under the tradename Cloisite clays 10A, 20A, 6A, 15A, 30B, or 25A.

The compounds comprising at least one (halogenated) copolymer mayfurther contain other ingredients selected from the group consisting ofantioxidants, foaming agents, anti-aging agents, heat stabilizers, lightstabilizers, ozone stabilizers, processing aids, plasticizers,tackifiers, blowing agents, dyestuffs, pigments, waxes, extenders,organic acids, inhibitors, metal oxides, and activators such astriethanolamine, polyethylene glycol, hexanetriol, etc., which are knownto the rubber industry. These ingredients are used in conventionalamounts that depend, inter alia, on the intended use.

Fillers may be present in the compounds comprising at least one(halogenated) copolymer in an amount of 1 to 100 phr, or 3 to 80 phr, or5 to 60 phr, or 5 to 30 phr, or 5 to 15 phr based on the total amount ofrubber in the compound (phr).

The compounds comprising at least one (halogenated) copolymer furthercontain a curing system which allows them to be cured to obtain thecopolymer vulcanizates.

The choice of curing system suitable for use is not particularlyrestricted and is within the purview of a person skilled in the art. Incertain embodiments, the curing system may be sulphur-based,peroxide-based, resin-based or ultraviolet (UV) light-based.sulfur-based curing system may comprise: (i) at least one metal oxidewhich is optional, (ii) elemental sulfur and (iii) at least onesulfur-based accelerator. The use of metal oxides as a component in thesulphur curing system is well known in the art and preferred.

A suitable metal oxide is zinc oxide, which may be used in the amount offrom about 1 to about 10 phr. In another embodiment, the zinc oxide maybe used in an amount of from about 2 to about 5 phr. Elemental sulfur,is typically used in amounts of from about 0.2 to about 2 phr. Suitablesulfur-based accelerators may be used in amounts of from about 0.5 toabout 3 phr.

Non-limiting examples of useful sulfur-based accelerators includethiuram sulfides (e.g. tetram ethyl thiuram disulfide (TMTD)),thiocarbam ates (e.g. zinc dimethyl dithiocarbamate (ZDMC), zinc dibutyldithiocarbamate (ZDBC), zinc dibenzyldithiocarbamate (ZBEC) and thiazylor benzothiazyl compounds (e.g. 4-morpholinyl-2-benzothizyl disulfide(Morfax), mercaptobenzothiazol (MBT) and mercaptobenzothiazyl disulfide(MBTS)). A sulphur based accelerator of particular note ismercaptobenzothiazyl disulfide.

Depending on the specific nature and in particular the level ofunsaturation of the (halogenated) copolymers peroxide based curingsystems may also be suitable. A peroxide-based curing system maycomprise a peroxide curing agent, for example, dicumyl peroxide,di-tert-butyl peroxide, benzoyl peroxide, 2,2′-bis(tert.-butylperoxydiisopropylbenzene (Vulcup 40KE), benzoyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)-hexyne-3, 2,5-dimethyl-2, 5-di(benzoylperoxy)hexane, (2,5-bis(tert-butylperoxy)-2, 5-dimethyl hexane and the like.One such peroxide curing agent comprises dicumyl peroxide and iscommercially available under the name DiCup 40C. Peroxide curing agentsmay be used in an amount of about 0.2-7 phr, or about 1-6 phr, or about4 phr. Peroxide curing co-agents may also be used. Suitable peroxidecuring co-agents include, for example, triallyl isocyanurate (TAIC)commercially available under the name DIAK 7 from DuPont, N,N′-m-phenylene dimaleimide known as HVA-2 from DuPont or Dow), triallylcyanurate (TAC) or liquid polybutadiene known as Ricon D 153 (suppliedby Ricon Resins). Peroxide curing coagents may be used in amountsequivalent to those of the peroxide curing agent, or less. The state ofperoxide cured articles is enhanced with copolymers comprising increasedlevels of unsaturation, for example a multiolefin content of at least0.5 mol.

The compounds comprising at least one (halogenated) copolymer may alsobe cured by the resin cure system and, if required, an accelerator toactivate the resin cure.

Suitable resins include but are not limited to phenolic resins,alkylphenolic resins, alkylated phenols, halogenated alkyl phenolicresins and mixtures thereof.

When used for curing (halogenated) copolymer, a halogen activator isoccasionally used to effect the formation of crosslinks. Such activatorsinclude stannous chloride or halogen containing polymers such aspolychloroprene. The resin cure system additionally typically includes ametal oxide such as zinc oxide.

Chlorobutyl and Bromobutyl can also self-cure without the need for anadditional halide source.

Halogenated resins in which some of the hydroxyl groups of the methylolgroup are replaced with, e.g., bromine, are more reactive. With suchresins the use of additional halogen activator is not required.

Illustrative of the halogenated phenol aldehyde resins are thoseprepared by Schenectady Chemicals, Inc. and identified as resins SP 1055and SP 1056. The SP 1055 resin has a methylol content of about 9 toabout 12.5% and a bromine content of about 4%. whereas the SP 1056 resinhas a methylol content of about 7.5 to about 11% and a bromine contentof about 6%. Commercial forms of the nonhalogenated resins are availablesuch as SP-1044 with a methylol content of about 7 to about 9.5% andSP-1045 with a methylol content of about 8 to about 11%.

The selection of the various components of the resin curing system andthe required amounts are known to persons skilled in the art and dependupon the desired end use of the rubber compound. The resin cure as usedin the vulcanization of (halogenated) copolymers comprisingunsaturation, and in particular for (halogenated) copolymers isdescribed in detail in “Rubber Technology” Third Edition, MauriceMorton, ed. , 1987, pages 13-14, 23, as well as in the patentliterature, see, e.g., U.S. Pat. Nos. 3,287,440 and 4,059,651.

The compounds comprising at least one (halogenated) copolymer may becompounded together using conventional compounding techniques. Suitablecompounding techniques include, for example, mixing the ingredientstogether using, for example, an internal mixer (e.g. a Banbury mixer), aminiature internal mixer (e.g. a Haake or Brabender mixer) or a two rollmill mixer. An extruder also provides good mixing, and permits shortermixing times. It is possible to carry out the mixing in two or morestages, and the mixing can be done in different apparatuses, for exampleone stage in an internal mixer and one stage in an extruder.

For further information on compounding techniques, see Encyclopedia ofPolymer Science and Engineering, Vol. 4, p. 66 et seq. (Compounding).Other techniques, as known to those of skill in the art, are furthersuitable for compounding.

The compounds described above may be cured to obtain the copolymervulcanizates.

Curing parameters depend on the curing system employed and are wellknown to those skilled in the art and are exhaustively disclosed in thedocuments cited hereinabove.

In one embodiment of the invention, the amount of (halogenated)copolymer in the vulcanizate is from 1 to 100 phr, or 10 to 100 phr or25 to 100 phr, or 50 to 100 phr, or 70 to 100 phr, or 85 to 100 phrbased on the total weight of the vulcanizate.

In one embodiment of the invention, vulcanizates comprising copolymer incontact with oxymethylene ether or medium comprising oxymethylene etherare used in (but not limited to) form of a belt, hose, o-ring,wire/cable, innerliner, shock absorber, machinery mounting, storage tanklining, storage tank, electrical insulation, bearing, container closureor lid; a seal or sealant, such as a gasket or caulking; diaphragm,curing bladder, fuel lines, fuel filters, membranes for fuel filtrationor a tank sealing.

It was surprisingly found that the copolymer vulcanizates exhibit a lowswelling in contact with oxymethylene ether.

Copolymers are commercially available and its production is describedmultiple times and well known to those skilled in the art.

(b) Medium Comprising Oxymethylene Ether (OME-medium)

(b.1) Oxymethylene ether (OME) including (poly)oxymethylene dialkylether(POMDAE; dialkyl polyformal) according to this invention are compoundsaccording to the general formula (I)

wherein

n is 0 to 5, preferably 1 to 5, more preferably 2 to 5, even morepreferably 3 to 5,

R¹ is linear or branched chain C₁-C₂₀-alkyl, preferably C₁-C₄-alkyl,more preferably methyl, ethyl or propyl, even more preferably methyl orethyl, and

R² is linear or branched chain C₁-C₂₀-alkyl, preferably C₁-C₄-alkyl,more preferably methyl, ethyl or propyl, even more preferably methyl orethyl.

The alkyls may be substituted or unsubstituted.

OME0: Dimethyl Ether (DME)

Dimethyl ether (DME; CH₃—O—CH₃) is oxymethylene ether according to thegeneral formula (I) wherein n is 0 and R¹ and R² are methyl. DME can bevery easily produced from methanol by catalytic dehydration or directlyfrom synthesis gas (CO and H₂). DME has been widely tested as a dieselfuel with good results. DME produces very small amounts of soot duringcombustion and so permits significant engine-based NOx reduction. Thephysical characteristics of DME are listed in Tables 1. DME has aboiling point of −24° C. and must be handled as a liquid gas in pressuretanks. This represents a disadvantage in terms of supply chain andvehicle technology compared to conventional liquid fuels. DME iscommercially available at Oberon Fuels.

OME1: Mono-oxymethylene Ether

Mono-oxymethylene ether (OME1; dimethylformal) is oxymethylene etheraccording to the general formula (I) wherein n is 0 and R¹ and R² aremethyl. OME1 is synthesized from methanol and formaldehyde. The cetanenumbers of OME1 vary between 29 and 37.6. OME1's viscosity issubstantially lower than that of diesel.

OME2-5: Polyoxymethylene Ether

The insertion of an n number of oxymethylene groups (—O—CH₂—) into theDME molecule produces oligomeric oxymethylene dimethyl ether (OME2-5)with higher molecular weights and boiling points of 42, 156, 201 and242°C. (at n=1, 3, 4 and 5). OME2-5 is made by converting OME1 withtrioxane at 80 ° C. in a reactive distillation system. Trioxane isproduced commercially by trimerisation of CH₂O.

In a preferred embodiment, the OME according to this invention ispolyoxymethylene dimethvlether (POMDME) according to general formula (I)with n≥2.

The physical properties of these OMEs depend on the chain length n. DMEis a gas under standard conditions. Short chain OMEs (OME1-OME5) arecolorless, flammable liquids. Compositions comprising OME3-OME5 fulfillto a large extent the physical properties of conventional diesel fuel.If the chain length is n≥6 (OME6 or higher), the OMEs are solid. Thephysical properties, flash points and cetane numbers of DME (n=0) andselected OMEs (n=1and a mixture of n=3, 4, 5) are listed in Table1. TheOMEs can be mixed with diesel fuel in any ratio.

Table 1 provides an overview of C1 fuels for diesel engines and theirproperties:

MolW Density Fp. Bp. CN OME Formula [g/mol] [kg/l] 15° C. [° C.] [° C.][° C.] 0 C₂H₆O 46.1 0.67 −140 −24.9 60 1 C₃H₈O₂ 76.1 0.87 −105 42.3 381a 260.5 0.88 −22 44.0 48 3/4/5^(a) C₆H₁₄O₅ 166.2 1.07 −19 155-242 72 DFCH_(1.86)O_(0.05) 250 0.83 −20 160-380 >51

Physical properties (molecular formula, molecular weight, density,freezing point, boiling point, cetane number) of C1 fuels for dieselengines: DME (n=0), OME fuels and, for comparison, diesel fuel (DF) inaccordance with DIN EN 590:2010.OME1a=OME1 with additives; ^(a)mixtureOME3/4/5: 36/37/27% by weight

Process for the Production of OME

OME can be produced according to one of the processes as disclosed inDE-A-102017201691, EP-A-1893667 or EP-A-1893660.

For example, synthesis gas (CO+H₂) is synthesized to methanol in a firststep and then, methanol vapor is partly oxidized and partly dissociatedcatalytically on an Ag mesh to form CH₂O by substoichiometric additionof air (methanol ballast process). DME is a side product of thisreaction. Excess methanol and the produced CH₂O are condensed out of theexhaust gas and converted to OME1 on an ion exchange resin.

(b.2) Medium

A medium according to this invention is a liquid hydrocarbon.

Suitable hydrocarbons are motor fuel, gasoline for aviation, marinefuel, jet fuel, heavy petrol, kerosene, lamp oil, coal oil, specialfuel, diesel fuel, fuel oil, engine oil, aircraft oil, turbine oil,hydraulic oil, grease, bitumen, petroleum wax, petroleum coke,preferably motor fuel and diesel fuel. OME can be mixed with medium inany ratio. The amount of OME in the medium according to this inventionis 0.01 to 100 wt.-%, preferably 0.1 to 100 wt.-%, more preferably 1 to100 wt.-% and even more preferably 5 to 75 wt.-% and most preferably 10to 25 wt.-%.

The present invention further relates to a device comprising

(i) a vulcanizate comprising copolymer and

(ii) a medium comprising oxymethylene ether,

wherein the vulcanizate (i) is in contact with the medium (ii).

In one embodiment of the invention, the devices according to theinvention comprise the copolymer vulcanizate (i) in form of a belt,hose, o-ring, wire/cable, innerliner, shock absorber, machinerymounting, storage tank lining, storage tank, electrical insulation,bearing, container closure or lid; a seal or sealant, such as a gasketor caulking; diaphragm, curing bladder, fuel lines, fuel filters,membranes for fuel filtration or a tank sealing.

In one embodiment of the invention, the devices according to theinventions comprise a vehicle such as car, truck or motorcycle, agasoline tank, a gasoline pump or a gas station.

In one embodiment of the invention, the oxymethylene ether of medium(ii) is a compound according to the general formula (I)

wherein

n is 0 to 5, preferably 1 to 5, more preferably 2 to 5, even morepreferably 3 to 5,

R¹ is linear or branched chain C₁-C₂₀-alkyl, preferably C₁-C₄-alkyl,more preferably methyl, ethyl or propyl, even more preferably methyl orethyl, and

R² is linear or branched chain C₁-C₂₀-alkyl, preferably C₁-C₄-alkyl,more preferably methyl, ethyl or propyl, even more preferably methyl orethyl.

In one embodiment of the invention, the oxymethylene ether of medium(ii) is oxymethylene ether according to general formula (I), wherein nis 0 and R¹ and R² are each methyl (OME1).

Device according to any of claims 1 to 6, characterized in that amountof oxymethylene ether according to general formula (I) is 0.01 to 100wt.-%, preferably 0.1 to 100 wt.-%, more preferably 1 to 100 wt.-% andeven more preferably 5 to 75 wt.-% and most preferably 10 to 25 wt.-%,based on the total weight of the medium (ii).

In one embodiment of the invention, devices comprise as a medium (ii)OME1 or diesel fuel comprising 0.01 to 99.9 wt.-% OME1.

The present invention further relates to the use of a copolymervulcanizate as a component of a device, wherein the vulcanizate is incontact with medium comprising oxymethylene ether.

The advantage of the present invention is the low swelling of copolymervulcanizates when in contact with media comprising oxymethylene ether.

Experimental Section:

Swelling: Samples of the rubber compounds were stored for 168 hours at70° C. in pure OME1 in accordance with DIN ISO 1817 in order todetermine the swelling, e.g. to measure the increase in mass and volumeafterwards.

Material: HNBR Hydrogenated nitrile rubber (Therban ® 3407 and 4307;ARLANXEO) (solubility parameter: 20.7 and 21.7 MPa^(1/2)) HNBR LTAcrylated hydrogenated nitrile rubber (Therban ® LT 1707; ARLANXEO)(solubility parameter: 19.8 MPa^(1/2)) EPDMEthylene-propylene-diene-rubber (Keltan ® 5260Q; ARLANXEO) (solubilityparameter: 16-17 MPa^(1/2)) SBR Styrol-butadien-rubber (Buna SE 1712 TE;Buna SE 1502 H, Arlanxeo Deutschland GmbH) (solubility parameter: 17.4MPa^(1/2)) BR Butadiene rubber (Buna CB 24; ARLANXEO)(neodymium-catalyzed; Mooney viscosity (1 + 4 @100° C.): 44) (solubilityparameter: 17 MPa^(1/2)) IIR Butyl rubber (X_Butyl ® RB301; ARLANXEO)(solubility parameter: 16.5 MPa^(1/2)) CIIR Chlorobutyl rubber(X_Butyl ® CB 1240; ARLANXEO; chlorinated isobutylene-isoprene- rubber;Halogen content (wt %): 1.25; Mooney viscosity (ML (1 + 8) 125° C.): 38MPa^(1/2)) FKM Fluroelastomer (Viton ® GLT 600 s; DuPont) (solubilityparameter: 17.8 MPa^(1/2)) OME Oxymethylene ether (Solvalid DMM 100;Ineos Paraform) NR Natural rubber (SMR CV60) Aflux ® 42 Fatty acidmixture; LANXESS Deutschland GmbH Escorez ® Tackifying Resin;ExxonMobile 1102 Kettlitz ®- triallylisocyanurate; Kettlitz-Chemie GmbH& Co. KG TAIC 70 Luvomaxx ® 4,4′-Bis-(1,1-dimethylbenzyl)-diphenylamine;CDPA Lehmann and Voss Maglite ® DE Magnesium oxide; C P Hall. N330Carbon black; Cabot VULCAN 3 N550 Carbon black; Orion Engineered CarbonSTERLING 6630 N774 Carbon black; Orion Engineered Carbon N990 Carbonblack; Lehmann and Voss Luvomaxx ® MT Perkadox ®Di(tert.-butylperoxyisopropyl)benzol 40% supported 14-40 B-PD on silica;Akzo Nobel Polymer Chemical Polyglykol Polethylene glycol (mean Mw of4000); Clariant 4000 S Resin SP Alkylphenols/formaldehyde resins; SIGroup 1068 Pellets Rhenofit ® 70% Trimethylolpropane trimethacrylate 30%TRIM/S supported on silica; LANXESS Silfit ® Z91 Combination ofcorpuscular silica and lamellar kaolinite; Hoffmann Mineral Spheron ®Carbon black; Cabot 5000 A Spider Sulphur Sulphur; Hallstar Stearic acidTriple pressed stearic acid; Akrochem (triple pressed) CorporationSulfads N,N'-Dipentamethylen-thiuramhexasulfid; R. T. VanderbiltSunpar ® Paraffinic process oil; Hallstar 2280 Tremin ® Vinylsilanecoated Wollastonite; Quarzwerke 283-600 VST Trigonox ®2,5-Dimethyl-2,5-di(tert-butylperoxy)hexane; 101-45D PD AkzoNobelUniplex ® 546 Tris-2-ethylhexyl trimellitate; LANXESS Vivatec ® 500Mineral oil; H&R Group (TDAE oil) Vulkacit ® CZ/N-cyclohexyl-2-benzothiazolesulfenamide; EG-C (CBS) LANXESS Vulkacit ®Di(benzothiazol-2-yl) disulfide; LANXESS DM/C (MBTS) Vulkacit ®Tetramethyl thiuram disulphide; LANXESS THIURAM/C TMTD Vulkanox ®N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine; 4020 LG LANXESS(6PPD) Vulkanox ® 2,2,4-Trimethyl-1,2-dihydrochinolin; LANXESS HS/LGVulkanox ® 4- and 5-Methyl-2-mercapto-benzimidazol; LANXESS MB2/MGVulkanox ® Zinc salt of 4- and 5-Methyl-2-mercapto-benzthiazol; ZMB2/C5LANXESS Vulkasil ® Precipitated sodium aluminum silicate; LANXESS A1Zinc oxide Zinc oxide (ZnO), LANXESS active Zoco ® 104 Zinc oxide;Hallstar

Compounding Procedure

Compounds listed in tables 2-4 inclusively were mixed according to thefollowing procedure:

Stage 1 was mixed using a Brabender lab mixer equipped with Banburyrotors having a mixing capacity of 375 cc at a mixing speed of 60 rpm,starting temperature of 60° C. (fill factor of 75). 30 seconds after thepolymers were added, half amount of carbon black was added. After 90seconds, the remaining carbon black, oil, stearic acid an additives wereadded. The compound (Stage 1) was discharged after 300 seconds or amaximum dump temperature of 150° C. The compound was cooled on a 50° C.mill (10×20 mill) and rested for a minimum of 8 hours before stage 2(curatives). Stage 2 was mixed using a 6×12 inch Mill (Capacity: 375.0),with a Roll Temperature of 30° C.

Compound from stage 1 were added on the mill until banding, and was thenblended with curatives. The compound was refined using ¾ cuts every 30seconds for 3 minutes. The compound was rolled to disperse allingredients and sheets with a thickness of 2 mm were formed.

Compounds listed in tables 5 and 6 were mixed according to the followingprocedure in an internal mixer (Banbury mixer):

A laboratory size Banbury internal mixer cooled at 40° C. was used toprepare the Examples. Rotor speed was held constant during mixing at 40rpm. The rubber was initially charged and mixed for one minute.Subsequently, the filler and additives (except peroxide and crosslinkingagents) were added. The compound was discharged once 140° C. wasreached. The compound was cooled on a two roll mill. After a minimum of8 hours cooling time the compound was put on at two roll mill at 40° C.and peroxide and crosslinking agents added. The compound was mixed untilall ingredients were well dispersed.

Curing

Cure behavior was determined by a MDR 200 (Moving Die Rheometer) (1degree arc, 160 C). Compounds described in tables 2-4 were then formedinto macro sheets (2 mm thickness) and cured at 160° C. in a compressionmold according to standard lab practices for t90+5 min curing time.Compounds in tables 5 and 6 were press cured for 10 min at 180° C.

TABLE 2 Swelling of IIR and CIIR compounds in OME-medium CHLOROBUTYL CB1240 100 70 30 BUTYL 301 100 SMR CV60 Natural rubber 0 30 70 N774 0 7070 N330 70 0 0 50 Escorez ® 1102 0 10 10 Maglite ® DE 0.5 0 0 Sunpar ®2280 5 10 10 10 Vulkanox ® HS/LG 1 2 2 Resin SP 1068 Pellets 3 0 0Stearic acid (triple pressed) 1 2 2 1 Vulkacit ® THIURAM/C TMTD 1 1 11.5 Zoco ® 104 5 5 5 5 Vulkacit ® DM/C (MBTS) 2 2 2 1 Spider Sulphur 01.5 1.5 1.5 Sulfads 1.5 mass increase 23 17 26 15 volume increase 34 2839 24 Butyl rubber shows a volume increase of only 24%. Chlorinatedbutyl rubber shows a volume increase of 34%.

TABLE 3 Swelling of BR compounds in OME-medium BUNA CB 24 30 70 100 SMRCV60 Natural rubber 70 30 0 Zoco ® 104 2 2 2 N550 STERLING 6630 60 60 60Vulkanox ® 4020 LG (6PPD) 2 2 2 Stearic acid (triple pressed) 3 3 3Vulkanox ® HS/LG 3 3 3 Vivatec ® 500 (TDAE oil) 20 20 20 Vulkacit ®CZ/EG-C (CBS) 1.4 1.2 1.03 Spider Sulphur 1.4 1.2 1.03 mass increase 6155 50 volume increase 83 77 71

TABLE 4 Swelling of NR and SBR compounds in OME-medium Buna SE 1712 TE 00 0 0 96.25 41.25 Buna SE 1502 H 0 30 70 100 0 0 SMR CV60 Natural rubber100 70 30 0 30 70 Zoco ® 104 2 2 2 2 2 2 N550 STERLING 6630 80 80 80 8080 80 Vulkanox ® 4020 LG (6 2 2 2 2 2 2 PPD) Stearic acid (triple 3 3 33 3 3 pressed) Vulkanox ® HS/LG 3 3 3 3 3 3 Vivatec ® 500 (TDAE 30 30 3030 3.75 18.75 oil) Vulkacit ® CZ/EG-C 1.5 1.5 1.5 1.5 1.5 1.5 (CBS)Spider Sulphur 1.4 1.4 1.4 1.4 1.4 1.4 mass increase 60 49 54 47 53 57volume swell 87 71 78 71 78 83 Natural rubber shows a volume increase of87%. Polybutadiene rubber (Buna CB 24) shows a volume increase of 71%.Styrene-butadiene-rubber (Buna SE 1502 H) shows a volume increase of71%.

TABLE 5 Swelling of EPDM + FKM compounds in OME-medium VITON GLT 600 S100 KELTAN 5260Q 100 SUNPAR 2280 5 Luvomaxx ® MT N-990 20 Tremin ®283-600 VST 55 65 Spheron ® 5000 A 40 Luvomaxx ® CDPA 1 1.5 Vulkanox ®MB2/MG 0.3 Vulkanox ® HS/LG 1.5 Vulkanox ® ZMB2/C5 1.5 Maglite ® DE 5Zinc oxide active 3 Polyglykol 4000 S 1.5 Aflux ® 42 0.5 Rhenofit ®TRIM/S 1.4 Kettlitz ®-TAIC 70 3 Trigonox ® 101-45D PD 3 Perkadox ® 14-40B-PD 7.5 mass increase 26 41 volume increase 40 102

TABLE 6 Swelling of HNBR compounds in OME-medium THERBAN ® 4307 100THERBAN ® 3407 100 100 THERBAN ® LT 1707 VP 100 Luvomaxx ® MT N-990 10050 100 Tremin ® 283-600 VST 35 Silfit ® Z91 80 Vulkasil ® A1 20Uniplex ® 546 10 10 10 Luvomaxx ® CDPA 1.5 1.2 1.5 1.5 Vulkanox ® MB2/MG0.3 0.4 0.3 0.3 Maglite ® DE 3 3 Zinc oxide active 3 3 Rhenofit ® TRIM/S1.5 1.5 Kettlitz ®-TAIC 70 2 2 Perkadox ® 14-40 B-PD 7.5 8 9.5 7.5 massincrease 25 30 37 64 volume increase 40 48 55 96 FKM (VITON GLT 600 S)shows a volume increase of 102%. EPDM (KELTAN 5260Q) shows a volumeincrease of 40%.

Hydrogenated nitrile rubber (THERBAN® 4307) shows a volume increase of40%. The swelling increases with the decrease of acrylonitrile contentin the HNBR.

What is claimed is:
 1. A device comprising: (i) a vulcanizate comprisingone or more polymers including a halogenated copolymer and (ii) a mediumcomprising oxymethylene ether, wherein the vulcanizate (i) is in contactwith the medium (ii).
 2. The device according to claim 1, characterizedin that the vulcanizate (i) is in a form of a belt, a hose, an o-ring, awire/cable, an innerliner, a shock absorber, a machinery mounting, astorage tank lining, a storage tank, an electrical insulation, abearing, a container closure or lid; a seal or sealant, a diaphragm, acuring bladder, a fuel line, a fuel filter, a membranes for fuelfiltration or a tank sealing, a vehicle, a gasoline tank, a gasolinepump or a gas station.
 3. The device according to claim 1, characterizedin that an amount of the halogenated copolymer is from 1 to 100 phrbased on the total weight of the one or more polymers.
 4. The deviceaccording to claim 1, characterized in that the halogenated copolymer isisobutylene-isoprene rubber (IIR), bromobutyl rubber (BIIR) orchlorobutyl rubber (CIIR).
 5. The device according to claim 1,characterized in that the oxymethylene ether is a compound of thegeneral formula (I)

wherein n is 0 to 5, R¹ is linear or branched chain C₁-C₂₀-Alkyl, and R²is linear or branched chain C₁-C₂₀-Alkyl,
 6. The device according toclaim 5, characterized in that the oxymethylene ether of medium (ii) isoxymethylene ether according to general formula (I), wherein n is 1 andR¹ and R² are each methyl (OME1).
 7. The device according to claim 5,characterized in that amount of oxymethylene ether according to generalformula (I) is 0.01 to 100 wt.-%, based on the total weight of themedium (ii).
 8. A method comprising a step of: contacting a vulcanizatescomprising copolymer, with oxymethylene ether or media comprisingoxymethylene ether.
 9. The method of claim 8, wherein the vulcanizatesis in a form of a belt, a hose, an o-ring, a wire/cable, an innerliner,a shock absorber, a machinery mounting, a storage tank lining, a storagetank, an electrical insulation, a bearing, a container closure or lid; aseal or sealant, a diaphragm, a curing bladder, a fuel line, a fuelfilter, a membrane for fuel filtration or a tank sealing.
 10. The deviceaccording to claim 2, wherein an amount of the halogenated copolymer inthe vulcanizate is from 25 to 100 phr, based on a total weight of theone or more polymers of the vulcanizate.
 11. The device of claim 6,wherein the halogenated copolymer is isobutylene-isoprene rubber (IIR),bromobutyl rubber (BIIR) or chlorobutyl rubber (CIIR).
 12. The device ofclaim 5, wherein the halogenated copolymer is isobutylene-isoprenerubber (IIR), bromobutyl rubber (BIIR) or chlorobutyl rubber (CIIR). 13.The device of claim 12, wherein n is 1 to 5, R¹ is C₁-C₄-Alkyl, and R²is C₁-C₄-Alkyl.
 14. The device of claim 12, wherein n is 1 to 5, R¹ ismethyl, ethyl or propyl, and R² is methyl, ethyl or propyl.
 15. Thedevice of claim 12, wherein R¹ is methyl, and R² is methyl.
 16. Thedevice of claim 12, wherein an amount of oxymethylene ether according togeneral formula (I) is 0.01 to 100 wt.-%, based on a total weight of themedium (ii).
 17. The device of claim 12, wherein an amount ofoxymethylene ether according to general formula (I) is 1 to 100wt.-%—based on a total weight of the medium (ii).
 18. The device ofclaim 12, wherein an amount of oxymethylene ether according to generalformula (I) is 5 to 75 wt.-%, based on a total weight of the medium(ii).
 19. The device of claim 1, wherein an amount of oxymethylene etheraccording to general formula (I) is 1 to 100 wt.-%13 based on a totalweight of the medium (ii).
 20. The device of claim 17, wherein n is 1,R¹ is methyl, and R² is methyl.